Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

A320 pro-abn eng 1(2) aircraft fadec supply

Tech Log The very best in practical technical discussion on the web

A320 pro-abn eng 1(2) aircraft fadec supply

Old 7th Aug 2013, 08:07
  #1 (permalink)  
Thread Starter
 
Join Date: Jul 2010
Location: Mumbai
Age: 33
Posts: 120
Likes: 0
Received 0 Likes on 0 Posts
A320 pro-abn eng 1(2) aircraft fadec supply

ENG 1(2) AIRCRAFT FADEC SUPPLY

INOP SYS : REVERSER 1(2)

Any specific reason for Reverser being inop?
gAMbl3 is offline  
Old 7th Aug 2013, 08:57
  #2 (permalink)  
 
Join Date: Feb 2003
Location: Wherever
Posts: 77
Likes: 0
Received 0 Likes on 0 Posts
One of the FADEC functions is the thrust reverser control.

On the other hand ,the aircraft supplies the FADEC during 5 minutes after the acft. is energized, and when the IGN/START is selected and below 12%N2. Above 12%N2 the FADEC is self powered. The acft. will supply the FADEC again when the MASTER SWITCH is off and below 12%N2, for 5 minutes.

I may be wrong, but youīre not going to use the reverser, anyway.
Flappo is offline  
Old 7th Aug 2013, 10:06
  #3 (permalink)  
Thread Starter
 
Join Date: Jul 2010
Location: Mumbai
Age: 33
Posts: 120
Likes: 0
Received 0 Likes on 0 Posts
We may get this fault in flight also during which FADEC is powered by its own alternator and will be self powered until N2 drops below 10% (IAE) or 12% (CFM). My question is why is Reverser inop in this case as it never lets N2 to drop below 10 or 12% ?
gAMbl3 is offline  
Old 7th Aug 2013, 11:08
  #4 (permalink)  
 
Join Date: Feb 2003
Location: Wherever
Posts: 77
Likes: 0
Received 0 Likes on 0 Posts
From where did you get this failure.......FCOM?
I was reviewing the Powerplant PRO ABN and I donīt have it.
Flappo is offline  
Old 7th Aug 2013, 14:43
  #5 (permalink)  
Thread Starter
 
Join Date: Jul 2010
Location: Mumbai
Age: 33
Posts: 120
Likes: 0
Received 0 Likes on 0 Posts
It's in PRO-ABN but I guess it's for IAE and not for CFM.
gAMbl3 is offline  
Old 7th Aug 2013, 15:13
  #6 (permalink)  
 
Join Date: Jun 2007
Location: Wanderlust
Posts: 3,235
Likes: 0
Received 0 Likes on 0 Posts
Throttle control lever sends reverse thrust command independantly to EIU, ECU. EIU closes inhibition relay switch and then only ECU deploy command goes through to hydraulic control unit which activates actuators through respective hydraulic system. In case of IAE, ECU is called EEC. Apparently it needs 28V DC. That is why REV inop.

Last edited by vilas; 7th Aug 2013 at 15:27.
vilas is offline  
Old 8th Aug 2013, 07:59
  #7 (permalink)  
 
Join Date: Feb 2003
Location: Wherever
Posts: 77
Likes: 0
Received 0 Likes on 0 Posts
gambl3, Rigth, I found it. Itīs for IAE engines.

Vilas, Thanks for the explanation.
Flappo is offline  
Old 9th Aug 2013, 06:48
  #8 (permalink)  
Thread Starter
 
Join Date: Jul 2010
Location: Mumbai
Age: 33
Posts: 120
Likes: 0
Received 0 Likes on 0 Posts
Thank you vilas.

Meaning due to lack of 28V dc aircraft supply the INHB RELAY SW will remain open and so no reverser deploy signal?
gAMbl3 is offline  
Old 9th Aug 2013, 08:33
  #9 (permalink)  
 
Join Date: Jun 2007
Location: Wanderlust
Posts: 3,235
Likes: 0
Received 0 Likes on 0 Posts
The diagram shows EEC/ FADEC getting aircraft 28V DC supply. Failure of this A/C 28V supply to both EEC channels may be unable to process deploy command causing REV inop.

Last edited by vilas; 9th Aug 2013 at 08:48.
vilas is offline  
Old 9th Aug 2013, 13:58
  #10 (permalink)  
 
Join Date: Mar 2013
Location: Siliconia
Age: 61
Posts: 44
Likes: 0
Received 0 Likes on 0 Posts
Gentlefolk,
One way to provide high integrity thrust reverse systems is to ensure that no one computer has all controls in its power.
Role [1] of the EIU is to take aircraft power and switch 28Vdc to the FADEC as required - as Flappo post #2.
Role [2] of the EIU is to take aircraft power and switch 28Vdc to the TR Isolation Valve solenoid, when required for Thrust Reverse operation.
Role [3] of the FADEC is to close the TR Isolation Valve solenoid circuit, when required for Thrust Reverse operation. N.B. the FADEC must not* power this circuit from either the 28Vdc EIU supply or from its dedicated generator systems.
Role [4] of the FADEC is to electrically power and actuate other TR valves, when required for Thrust Reverse operation.
* This particular electrical power isolation may have a permissible failure rate; the details are another story.
The combination of the above roles ensure that a TR system could only deploy with concurrent EIU and FADEC command.
I therefore speculate that the reason for the ECAM warning correlation between FADEC and TR operation, is due to electrical supply fault detection/reporting for these 28Vdc buses having shared hardware insdie the EIU.
0'n'1
noughtsnones is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell or Share My Personal Information

Copyright © 2023 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.